1. Field of the Invention
The invention relates to a swivel caster suitable to be mounted in a transportation system wherein the caster includes a wheel secured on a shaft by means of a first rolling bearing, said shaft being attached near its ends to the legs of a swivel fork including a body or supporting-element connected with a casing of a second rolling bearing wherein the casing can be mounted on said transportation system wherein the system includes a supporting or upper platform from which said caster wheel partly extends and a bottom platform on which said bearing casing can mounted.
2. Description of the Related Art
Such a swivel caster is known from the Dutch patent application 84 00460. This disclosure teaches that, for instance with transportation of relatively large and often heavy containers, a transportation system is used, a so-called roller platform. This system comprises a supporting structure whereupon swivel casters are mounted with the rolling bearings on the bottom platform of such system. Above this bottom platform a deck or upper platform is mounted from which only part of the swivel casters wheels extend and along which the transport or transfer of freight, respectively, will be carried out.
This transportation system or roller platform is particularly suitable for loading and/or unloading of cargo-planes when it must be possible to easily transfer the relatively heavy and often sizeable cases or containers in horizontal directions. The wheels of the swivel casters will actually rotate around a vertical axle over a certain distance, which axle is also the axle of a rolling bearing which is connected to the bottom platform. However, with the known transportation system this connection leads to problems which are mainly caused by the facts that;                bolt connections with the bottom platform are applied which means that during the assembling procedure the fact must be taken into consideration that the can accessibility of the platform-construction is limited;        the replacement of swivel casters must often be carried out by force, since the bolt connections may have corroded during operation;        the accessibility of the swivel casters that must be assembled is often seriously hindered by the platform design and the corroded bolt connections that are drawn to pieces.        